Standard deviation of patch area (Area and edge metric)
lsm_c_area_sd(landscape, directions = 8)tibble
Raster* Layer, Stack, Brick, SpatRaster (terra), stars, or a list of rasterLayers
The number of directions in which patches should be connected: 4 (rook's case) or 8 (queen's case).
$$AREA_{SD} = sd(AREA[patch_{ij}])$$ where \(AREA[patch_{ij}]\) is the area of each patch in hectares.
AREA_SD is an 'Area and Edge metric'. The metric summarises each class as the standard deviation of all patch areas belonging to class i. The metric describes the differences among patches of the same class i in the landscape.
Hectares
AREA_SD >= 0
Equals AREA_SD = 0 if all patches are identical in size. Increases, without limit, as the variation of patch areas increases.
McGarigal, K., SA Cushman, and E Ene. 2012. FRAGSTATS v4: Spatial Pattern Analysis Program for Categorical and Continuous Maps. Computer software program produced by the authors at the University of Massachusetts, Amherst. Available at the following web site: https://www.umass.edu/landeco/
lsm_p_area,
sd,
lsm_c_area_mn,
lsm_c_area_cv,
lsm_l_area_mn,
lsm_l_area_sd,
lsm_l_area_cv